Class InformationNumber: 175/4Name:Boring or penetrating the earth > Boring with explosion in inaccessible hole > Driving core receiver by explosion or with receptacle collecting material in boreDescription: Subject matter directed to an explosive apparatus which includes or is combined with (1) a core receiving barrel or tube which is propelled into the formation by an explosive charge or (2) a receptacle or the like which is described as adapted to collect and remove a sample of the formation from the hole.